DMO Anti-VEGF Regimens

How the DRCR Retina Network modified PRN algorithm compares with the dosing regimens of the phase 3 registration trials: mean change in best-corrected visual acuity (ETDRS letters) against the number of injections given, at 1 and 2 years, and at 3 and 4 to 5 years where follow-up exists. Select a mark or a table row for the regimen detail and its sources.

Vision gained against injections given

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Time point

Drugs

Strategies

Select a mark or a table row to see the regimen, the trial population and the sources.

All arms and time points

The drug and strategy buttons above the chart also filter this table. Each cell gives mean change in visual acuity from baseline in ETDRS letters, then the injection count from baseline to that time point. Italic counts are scheduled by protocol rather than observed. Numbers in superscript link to the sources listed at the foot of the page.

Arm	Drug	1 year	2 years	3 years	4–5 years	Notes

After the first year: VIOLET

VIOLET randomised 458 patients who had already received at least 1 year of aflibercept 2 mg to three maintenance strategies for 100 weeks. Vision was stable in all three (baseline here is the start of VIOLET, not the start of treatment), so the regimens differ mainly in workload.^VIO

Regimen	Change at week 52	Injections over 100 weeks	Clinic visits over 100 weeks
Treat-and-extend	+0.5 letters	10.0 (mean)	13.3
As needed (PRN)	+1.7 letters	11.5 (mean)	25.0
Fixed every 8 weeks	+0.4 letters	12.3 (mean)	16.1

Read across trials with care

Entry vision differs. Protocol I and T took 20/32 to 20/320; Protocol AC took 20/50 to 20/320 only; RISE and RIDE took 20/40 to 20/320. In Protocol T, eyes starting at 20/50 or worse gained about twice as much as eyes starting at 20/32 to 20/40.
Injection counts are reported in different ways: medians in DRCR papers, means in industry papers, and only the protocol schedule in VIVID, VISTA, RISE and RIDE. Scheduled counts slightly overstate what patients actually received.
RESTORE reports only the mean average change over months 1 to 12, which runs lower than the change at month 12. RETAIN month-12 values are shown.
Laser was allowed in most trials. Protocol T added laser after 6 months for persistent oedema in 41% to 64% of eyes.
Extension studies (Protocol T 5-year, RHONE-X) include only patients who returned, and RHONE-X moved all arms to faricimab treat-and-extend.

Dosing strategies

How the DRCR.net algorithm works

Protocol T rules. Vision (ETDRS letters) and OCT central subfield thickness are measured every 4 weeks in year 1 and every 4 to 16 weeks in year 2, depending on disease status and treatment.^PPT

Finding at the visit	Anti-VEGF
Improving: thickness down 10% or more, or vision up 5 letters or more	Inject
Worsening: thickness up more than 10%, or vision down more than 5 letters	Inject
Stable, but not yet across the last 2 injections	Inject
Stable across the last 2 injections, thickness below 250 µm and vision 20/20 or better	Defer
Stable across the last 2 injections, thickness 250 µm or more, or vision worse than 20/20	Inject before week 24; defer from week 24

Focal or grid laser, from week 24 only: given when thickness is 250 µm or more (or oedema threatens the fovea) and the eye has not improved over the last 2 injections; repeated no sooner than 13 weeks.^PPT Protocols I and AC used the same principles; Protocol AC added a switch from bevacizumab to aflibercept from week 12 when oedema persisted without improvement.^{I10, AC}

Sources

All figures are taken from the PubMed abstract or the open-access full text of the cited paper, except where a note says otherwise. Each source opens on PubMed; the DOI link opens the publisher's page.